Question #N737

A circle has a diameter of 10. What is the area of the circle, in terms of $\pi$?
A. 5$\pi$
B. 10$\pi$
C. 25$\pi$
D. 100$\pi$

Correct Answer is: C

The radius of a circle is half its diameter. So, the radius of this circle is 5. The area of a circle is $\pi r^2$, so the area of this circle is $\pi (5)^2 = 25\pi$.